The invention discloses a building lighting decoration device with a mosquito repellent function. The building lighting decoration device comprises lamp shells, a controller and a mosquito repellent device. The multiple lamp shells are connected together in an inserted manner to form a needed pattern, a model is convenient and simple, and installation and maintenance are easy. Through the arrangement of the mosquito repellent device, mosquitoes, flies, bugs and the like can be prevented from gathering around the lamp shells, and therefore building decoration attractiveness cannot be affected. Wire holes are formed below protruding points, and therefore when inserting and connecting are not convenient between the lamp shells, the lamp shells can be connected through wires. Three rows of LED lamps are arranged in the lamp shells so that pattern arrangement can be simpler, more convenient and more rapid, and the construction difficulty is lowered; meanwhile, the three rows of LED lamps are connected in parallel so that any row of LEDs can be conveniently maintained, and when one row of LEDs are in fault, lighting of the other two rows is not influenced, in other words, the influences on the building decoration effect are lowered to be minimal, and accordingly the maintaining and replacing frequency is reduced.